Various types of pipe are manufactured according to many different processes. For example, oil field pipe of three to four feet in diameter and 80 to 100 feet in length is frequently welded from sheet stock in a longitudinally continuous manner according to several simultaneous steps. The welding results in a weld bead along an external surface of the welded pipe that is removed to provide a smoother outer surface of the pipe.
A planing tool is placed in the path of travel of and in contact with the external surface of the moving welded pipe to remove the weld bead from the pipe in a continuous fashion, thereby generating a hot, sharp, and stringy separated bead. In older pipe manufacturing equipment, these stringy beads were initially manually attached to a spool, and then automatically wound to the spool during the welding and bead cutting process. But the process had to be interrupted periodically to change spools. In more recent pipe manufacturing processes, the stringy beads are redirected against the direction of travel of the welded pipe at an acute angle with respect to the weld bead on the pipe and fed into a separate material handling device opposite the planing tool and then chopped up by a rotary chopper.